Supplementary table for: A retrospective study on weaning glucocorticoids and recovery of the hypothalamic-pituitary-adrenal axis

Context
Glucocorticoids suppress the hypothalamic-pituitary-adrenal (HPA) axis resulting in tertiary adrenal insufficiency (AI). When weaning patients off glucocorticoids there is no consensus on whether to maintain patients on prednisolone or convert to hydrocortisone.
Objective
Investigate HPA axis recovery in patients on long-term prednisolone and assess outcome after hydrocortisone conversion.
Design
Retrospective cohort study.
Setting
Outpatient endocrine steroid clinic.
Patients
Patients on long-term prednisolone referred for HPA axis testing between 2015-2022.
Main outcomes measured
1) HPA axis recovery rate in patients on prednisolone demonstrated by normal ACTH stimulation test (AST).
2) HPA axis recovery rate sub-analysis of dose-matched patients with confirmed tertiary AI on prednisolone or hydrocortisone.
Results
206 patients on prednisolone were tested for tertiary AI. Of these 176 remained on prednisolone while 30 were converted to hydrocortisone. The overall HPA axis recovery rate for patients on prednisolone after interval testing was 137/206 (66.5%). HPA axis recovery rate in dose-matched prednisolone and hydrocortisone conversion groups was 7/10 (70%) and 2/13 (15%) (p=0.008), respectively. There was no difference in mean (SD) age (67.1(12.2) v 63.4(11.1) years; p=0.464) and baseline cortisol (5.3(4.2) v 4.6(3.1)µg/dL; p=0.648) and median [IQR] glucocorticoids duration (1213[1114] v 2316[4808] days; p=0.693) and baseline ACTH (20.5[29.0] v 16.3[14.8]ng/L; p=0.905) between dose-matched prednisolone and hydrocortisone groups. Follow-up duration in prednisolone group was significantly lower (median [IQR] 348[975] v 667[884] days; p=0.012).
Conclusions
Patients with glucocorticoid induced AI maintained on once-daily prednisolone can recover HPA axis function when weaning. There is no apparent advantage to recover HPA axis function in converting to multiple dosing hydrocortisone.